Robustness of Acoustic Scattering Cancellation to Parameter Variations

Sustainability

Claudia Guattari¹  Paola Gori¹  Roberto de Lieto Vollaro¹  Luca Evangelisti¹  Gabriele Battista¹  Carmine Basilicata¹  Alessandro Toscano² 

[1] Department of Engineering, Roma TRE University, Mechanical and Industrial Engineering Section, Via della Vasca Navale 79, 00146 Rome, Italy;;Department of Engineering, Roma TRE University, Applied Electronics Section, Via Vito Volterra 62, 00146 Rome, Italy; E-Mails:

关键词: acoustic metamaterial;    scattering cancellation;    Mie scattering;    acoustic cloaking;   

DOI  :  10.3390/su6074416

来源: mdpi

【 摘 要 】

This contribution aims at investigating the possibility to cloak a spherical object from an acoustic wave by applying the scattering cancellation approach. In electromagnetism, the scattering problem is treated using the Mie expansion technique, through which the scattered field by a spherical object can be represented as a superposition of TE and TM spherical harmonics. It is possible to extend this concept to the acoustic field by defining an analogous approach; the pressure field, generated by an elastic wave impinging on a spherical object, can be expressed applying the Mie expansion technique, as well. In acoustics, to achieve scattering suppression at a given frequency, the constitutive parameters to control are density and compressibility. By varying these parameter values, it is possible to define an engineered material with anomalous properties, which cannot be found in nature, able to reduce the scattering cross-section (SCS) from a spherical object. We propose a study about the effectiveness of the SCS reduction from an elastic sphere coated with a properly-designed acoustic metamaterial. The sensitivity of the SCS to parameter variations is analyzed for different coating thicknesses and sphere dimensions. Our analysis is supported by both the analytical modelling of the structure and numerical simulations.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.